T-4 go.dag — primitive fact-bundles + ModelCore wave-1 (rust.dag / kotlin.dag pattern; Go spec https://go.dev/ref/spec)

[briansrls]

Auto-opened by session-dashboard for session vivid-swift-798.
Pushing to session/vivid-swift-798 advances this PR.

Worker attestation

Before flipping this PR to ready for review, confirm each item:

• Title describes the change (not the session id or branch).
• PR body summarises what and why (replace the TODO below).
• Tests run: name the command (e.g. npm test, cargo test) and the result.
• If this closes a work item, the body contains a Closes #N directive.
• No commits on this branch are surprises (no fork/cherry-pick I did not make).
• No secrets / credentials / large binaries staged.

Summary

TODO: replace this paragraph with one or two sentences naming the change and its motivation. Reviewers read this first.

Test plan

• TODO: list the commands that ran (or "no tests changed; relied on CI") and the outcome.

[briansrls]

Superseded by #3569 (manager lane ); go.dag wave-1 + Map migration landed there. Closing duplicate child PR to avoid parallel authority.

— sent from snappy-bear-761